Economical Geology of Massachusetts. 375 



' A new method for learning the absorbmg quaUties of soils has 

 lately been practiced by M. Berthier,* which appears to us as 

 particularly deserving of notice. It consists in filling a small filter 

 with the dry soil, and then thoroughly moistening it until water 

 drops from it; when the water has ceased dropping, the filter 

 with its contents is transferred to one cup of a balance and a 

 moistened filter of the same size to the other, when the gain in 

 weight is noted. The following are some results obtained in this 

 way by Berthier : 



A vegetable soil from Ormeson, near Nemours, of a pale ochre 

 yellow color, taken from a vineyard and considered of excellent 

 quality, absorbed 0.36 its weight of water. 



Q,uartzy sand of Nemours, such as is employed in the glass fac- 

 tory of Bagneaux, absorbed 0.227. 



Q.uartzy sand of Aumont pulverized in a mortar, absorbed 0.30. 



The kaolin of Limoges, absorbed 0.46. 



The chalk of Meudon, when purified and in the condition of 

 Spanish white, gained by the process 0.35 its weight. 



The report contains likewise several interesting experiments 

 directed to the converse of this problem, viz. to ascertain the ca- 

 pacity of soils to retain water, which is by no means proportional 

 to their powers of absorption : for these results we must refer the 

 reader to the report. 



Prof Hitchcock comes at the following very just conclusions 

 in respect to the soils of Massachusetts, viz. that the grand desid- 

 erata in them are carbonate of lime and an additional supply 

 of geine, or organic matter. He then proceeds to point out nu- 

 merous sources of these materials in different sections of the state, 

 many of which have been brought to light in the progress of the 

 survey. 



An extensive bed of marl is pointed out as existing in the 

 northwest part of Stockbridge, in Berkshire county, on land of 

 Mr. Buck, a second in the same town, four miles from the court 

 house in Lenox, a third in the northeast part of Lee, (the thick- 

 ness of which in some places is ten feet.) also several beds in 

 West Stockbridge. Numerous other beds have also been noticed 

 in the neighboring towns. The purest of these marls when dry, 

 are white and much lighter than the common soil, and they ea- 



* Ann. des Mines, t. xiv, 1838. 



